caa a22 4500 397556608 CHVBK 20180308164804.0 cr unu---uuuuu 161202e199609 xx s 000 0 eng 10.1093/oxfordjournals.jbchem.a021453 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jbchem.a021453 Mapping Myosin-Binding Sites on Actin Probed by Peptides That Inhibit Actomyosin Interaction [Elektronische Daten] [Tsuyoshi Katoh, Fumi Morita] A 2-kDa peptide (2K peptide) which was derived from the neck region of porcine aorta smooth muscle myosin heavy chain binds to actin competitively with skeletal myosin subfragment I (S1) in the absence of ATP and inhibits acto-S1 ATPase activity [Katoh, T. and Morita, F. (1993) J. Biol. Chem. 268, 2380-2388]. Using this and other peptides, myosin-binding sites on actin were mapped and their functions were studied. The 2K peptide inhibited the acto-S1 ATPase activity without inhibiting the binding of S1 to actin in the presence of ATP. On the other hand, the dansylated 2K peptide (DNS-2K peptide) inhibited not only the acto-Sl ATPase activity but also the binding of S1 to actin in the presence of ATP. Then, DNS-2K peptide was crosslinked to actin with 1-ethyl-3[3-(dimethylamino)propyl]carbodiimide. Amino acid composition and sequencing analyses of the fluorescent lysylendopeptidase-peptides of the crosslinked product indicated that DNS-2K peptide was crosslinked to acidic residues within residues 1-18 (Asp1, Glu2, Asp3, Glu4, and/or Aspll), 19-60 (Asp25), and 85-113 (Glu99 or Glu100) of actin. A competition experiment for the crosslinking with unlabeled 2K peptide showed that the crosslinking to residues 85-113 of actin was specific for DNS-2K peptide. In addition, isolated actin peptide 85-113 was found to show the competitive inhibition of actin-activated ATPase activity of S1 with respect to actin. These results suggest that the site within residues 1-28 of actin participates in the actin-activation of myosin ATPase activity, and the site within residues 85-113 of actin participates in the weak binding of myosin to actin in the presence of ATP. © 1996 BY THE JOURNAL OF BIOCHEMISTRY Regular Papers nationallicence actin nationallicence actomyosin nationallicence acto-S1 nationallicence acto-S1 ATPase nationallicence myosin nationallicence Katoh Tsuyoshi Division of Chemistry, Graduate School of Science, Hokkaido University, Kita-ku, Sapporo 060 aut Morita Fumi Division of Chemistry, Graduate School of Science, Hokkaido University, Kita-ku, Sapporo 060 aut The Journal of Biochemistry Oxford University Press 120/3(1996-09), 580-586 0021-924X 120:3<580 1996 120 jbchem https://doi.org/10.1093/oxfordjournals.jbchem.a021453 text/html Onlinezugriff via DOI 1 other jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jbchem.a021453 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Katoh Tsuyoshi Division of Chemistry, Graduate School of Science, Hokkaido University, Kita-ku, Sapporo 060 aut NATIONALLICENCE 700 1- Morita Fumi Division of Chemistry, Graduate School of Science, Hokkaido University, Kita-ku, Sapporo 060 aut NATIONALLICENCE 773 0- The Journal of Biochemistry Oxford University Press 120/3(1996-09), 580-586 0021-924X 120:3<580 1996 120 jbchem Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford